Is it worth it to upgrade from a old 680i with the q6600 to the z170 Classified k with the i7 6700 k ?? Just curious on opinions. Thanks

Hello,
 
well Kabylake is right around the corner. If you are interested in the current Skylake CPU's I would consider it if the price was right. Otherwise I would wait.

Absolutely!..Virtually everything is mucho more fast/better/efficient..I went from a 790i FTW with a Q6600 (G0 stepping) OC'd to 3.6GHz to what's in my sig now and was blown away even with the 2600K at stock speed..You'll need a decent video card if don't have one and you're into gaming, but an i7-6700K does have on-chip graphics and the 'K' means unlocked multiplier for better OC'ing..Maybe waiting like MDecker said might be even better, up to you.
 
Intel specs
 
Intel Core 2 Quad Q6600 vs Core i7-6700K
 
In layman's terms: Pee-wee Herman vs Hulk Hogan

 
If you want to upgrade for the time being, then the 6700 would be a good choice.

Thanks for the input. Any clue if the new Kaby Lake can be ran on the z170 boards with a bios update?

Are you going to be mainly gaming? what resolution?  I'm on an i5 3570k and 1080 gtx.  I get slight stutters on certain games while on 1440p Ultra settings.  
 
I'm on the same boat and want to upgrade, but like EVGATech_MDecker said, kabylake is releasing pretty soon.  Trying my hardest to hold off until then lol.